Pump for mobile fire pumpers



H. E. LA BOUR PUMP FOR MOBILE FIRE PUMPERS.

Filed Sept. 2, 1959 v Jan. 9, 19 45.

3 Sheets-Sheet l w Jan. 9, 1945, .H.' E.L A BOUR I 2,367,032

' IRE PUMPER'S v QM tive andlreliable.

andficolnplexlifore'thm peculiar Patented Jan. 9, 1945" PATENT 10F FICE b if .@-2;s67,022

l rumironmoe pnr mn PUMiERS l- Harry-E; lialBounE lkhartplndr Applicat'iofiTSepternber 2, 1939, Serial No. 293,227 1 Clad-m. (euros-$1 153) Thewpresent invention relates to irnobiletfire pumpers. i-Fire fighting .aequipment as @preyiously organized,- has been-usdevelo'ped chiefiy ifor the purpose of protectingebuildings and equipment in congestedudistricts. Thism-inv olves two general provisions l namely; :a .water supply sys- .tem, including city watermainsto provide the necessary water supply, and elaborate and =ex-' pensive pumper trucks .maintained and .manned by pro-fessionalfire The chie-J-object -.-of. -the;.-.present invention tis to. :provide imeans :by V which it .is possible for a limited personnel, ,if necessary onewman, to transport Q-andl--.bringinto operationw against a fire a complete-.-high'fpressure,. motor .drivenrdfire present: invention-provides. the "fire efig hti-ngeart with a fire Idepartmenterequiringt a :minimum lot personnel, and Which'is fullyiseffective even with only one vman. Obvlu'sly',-- several mencan'vexpedite :ecertain of the roperations, particularly those 'oi icoupli'ngbup the: hose, -nevertheless;:on e man can; quickly transport andwbring theilunit into full .Operation.

-- For =the:iproteotionl:ofvcfarnrbuildings; {country r25 homes, 012 even isolated "communities, such as villages; a smallwtowns, lake cottages, deserts; and the like, such previously known aprovisionsi are. not justified; and .in some cases are :quiteout lot the question. The-:r.esult is #that' no suitable -means for fire fighting in such situationsshas heretofore beensavailablefl While in many such situations ample water. is; available; me awhile pumping equipment adequate to the needs ot fire ,fig htingsiunder those conditions .has'. been a developed. r

l. vam awareithat Jheretofore,s.= iparticularly r-in Europegthere: have. been .proposals to provide a ipumper forrfire protection .purposesxutilizingl-a centrifugal. pump as the pumping and; pressure developing/means. Since .in a mobile 'fire pumper it is;generally:necessaryfto -bera'ble;to raise the liquidlito ;the.'1pump the. usual centrifugal pump requires some additive means to prime the pump to iput; it vinto operation andxto' .1maintain this i prime i to; :continue; it :in .use: 2. I Schemes for utilizing the; suction cot an; internal-combustion engine or to employ 'an auxiliary airupump :has been proposed, butatheyrarenotfsufficientlyposi- Prior art pumpers employing ,arcentrifugal pumps with *priming' attachments and-auxiliaries are .toofiexpensivei and intricate. P They cost Itoo much i'in theifirst place; and "are too unreliable requirements rof TThe. mobile pumper lfighters=constantly on duty.

generally}assumedw that 'sliilled personnel will ope'ratefthe. same. U I

i which islherein disclosed aslfthe preferred lform. o'fpmy, invention. isfin- Jteiideatitot -'.be-..Iusedmby-"either professional fire fighters or;lb y =volur'1te'ers t with complete success. The pumping .e'1ement-. is lpreferably a high pressure 4 single stage selfepriin'ing centrifugal. .ipurnp witli ,only,.onel movable .part, i.- 'e., the impeller.

The'ur'i'it' is light and small compared. with pre- "viou'sly .known [.deYicesQ Impurities, and enipumper: IofFeflZecti-vecapacity.In:brief,v. the

solids,'-.cannotinterfere with the operation of \the ldevi ce. A single. person, who; is capable of operating an automobile, can hitch an automobile (even I the lightest passenger" .car

'onifthe market) tothel unit andvtransport itto theiplace of useland putit into operation; The concept of ,tajaidv automobile transportation by ability to.v hitchhthe unitias a. trailer: to the rear bum-per off any passenger automobile gives the unit; an availability heretofore unknown in apparatusi-for. this purpose, H v i T Il-fheunit is constructed and adapted for high speed transportation behind atpassenger automobile without ,previouspreparation,.since .a hitch, having a.-un iversal bumper type clamp and universal swivel connection, permits. the unitto bel hitehedtto' the bumper of any. automobile and-tobedrawnwherever a passenger car can bedriven. ,hnotable feature is the roadability or stability on, the'road of the bumper unit.. A trailerrchassis preferably having a tread .oistandard gauge is employ'ed; and by disposal of the parts whiche-involvetthe major weight practically in the-longitudinal ,median line of the trailer chassis 4 and substantially. balanced lore and aft, land with thercenter of, gravity as lowias possible a :degree- 'of stability and 1 roadability is .coverlthe'ground.

' automobile c secured-which will allowthe unitIto goat high speeduover -substantially. .any road t that is open to thelautomobile. v I;t can .takeany road that an automobile ,zcan itravelat any; speed that the be driven without substantially interfering. with; the. ability of the automobile. to

Inrany fire-fighting equipment reliability is .of

the utmostizimportanc'e. 1'\,eliability means that the .ieguipmentlmustbe ready to go at any instant and that when the equipment has been gotten to theJ-fire .it will= work immediately, and do'the I intended service quickly: .and efficiently.

Considered from; the standpoint ofa. loaded vehicle, the tpresent ir it is designedwith a low I center-lot; gravity; within-the weight properly $211 ranged for great stability-and capable of high speed transportation. The concept is more easily grasped by pointing out that in' the preferred embodiment the center of gravity of the pumper is substantially as low as or lower than the center of gravity of the automobile without any load. This is attained by disposing the chassis frame at substantially the level of the wheel axis, and disposing the pump and engine on the frame with their bottoms at substantially the same level as the bottom of the frame.

This means that the unit can be taken, from the place where it is normally kept, to the point of the fire in minimum time. Because of the mobility of the unit a' widely scattered community or group of buildings may rely upon this single inexpensive unit.

From the standpoint of operation as a pumper the simplicity and inherent reliability of the unit is outstanding. The pump has only one moving part which is the impeller and its shaft. The driving motor is preferably a compact self-contained multi-cylinder internal combustion engine arranged for operation under governor control at various desired speeds, and particularly at a relatively high speed of the order of 3000 R. P. M.,

so that it is compact and powerful for its weight. The pump is essentially of the self-priming centrifugal type. In the preferred form it employs the hydraulic balance or peripheral reentry principle in its operation of priming and pumping. The pump, in order to constitute an adequate fire-fighting unit, must develop pressures of the order of 100 pounds per square inch or above,

and must deliver a gallonage which will be'effective. The present unit will discharge 150 gallons per minute at 100 pounds per square inch pressure, with the engine running at approximately 2850 R. P. M. This capacity is more or less a standard requirement to meet present day insurance requirements and equipment standards as an effective pumper. The simplicity and inherent self-priming ability of the present pump,

together with its rapid self-priming, provides a fire-fighting equipment of great simplicity, reliability and effectiveness, which are essential for operation by the non-professional type of operator which must be relied upon to operate the unit.

The hydraulic balance type of self-priming pump is desirable for a number of reasons, some of which are as follows: This type of pump inherently regulates its own internal operation to expel the air as rapidly as possible consistent with retaining its vacuum. It is free of any delicate parts, such as valves or small passageways which tend to get out of order or become stopped up by impurities in the water or' otherwise bcome disabled. Since internal reversal of flow occurs in both the priming and in the main passageways where two passageways are used, the pump tends to keep itself clear of internal obstructions. The same advantage of being self-clearing is present in the single throat type. A bypass between discharge and suction portions of the impeller has pressure always in one direction and tends to become stopped up and hence become inoperative. An open by-pass between discharge and suction portions of the pump if large enough to produce rapid priming completely destroys the efficiency of the pump when operating at such high pressures as are here required. Air enterin the suction pipe does not cause the self-priming pump to become air bound.

A necessary part of the self-priming centrifugal pump is the charge of liquidemployed to effect self-priming. This is normally trapped within the body of the pump and its separator and intake trap, and provision is made to insure that that charge will be retained either within the pump or in an associated container when the unit is carried over the roughest of roads and subjected to vibration, turning corners, and bouncing over obstructions. Even in the case of accidental overturn, the liquid will be retained in the pump or in the associated container and be instantly available for service when called upon to operate even in cold weather. The operator may start the engine of the unit before making the run. It may be easier to start the engine before leaving the fire house or other storage place of the unit, and such starting of the engine may save the time of warming up while making the run. Under those circumstances, the means for retaining the priming charge is particularly desirable. This means does not, however, interfere in any way with the starting or running of the engine to warm it up.

For use under cold weather conditions when water would tend to freeze in the pump, the priming charge may consist of an anti-freeze solution. Alternatively, for use in winter time in cold climates, the charge of priming liquid consisting of an anti freeze solution or mixture, may be carried with the pump in a separate can or container which is definitely associated with the pumper, so that it will be available to serve as the priming charge when the pumper arrives at the place ofuse.

The pump in the preferred form is specially designed to develop the necessary high pressure in a single stage and within small dimensions and to operate at high efficiency. This is of the utmost importance, since weight and space must be kept at a minimum. The preferred form of pump herein shown is particularly designed and constructed for the present service to secure the necessary delivery pressure and volume in a small compact high speed device and to secure rapidity of priming. The particular unit herein shown will prime itself in sixteen seconds when using the full twenty-four feet of standard 3 inch suction hose with a 10 foot suction lift from the surface of the water to the pump. The speed of priming is important inasmuch as even a few seconds count in first getting water upon the fire.

A feature of the unit herein disclosed is that it is completely self-contained as to all the equipment necessary to take water from the source and deliver it onto the fire. The present unit is arranged and designed to carry the necessary length of suction hose and the necessary length of discharge hose with suitable wrenches, nozzles and strainer. Preferably, space is provided for 500 feet of 1 inch fire hose and two twelve foot lengths of 3 inch suction hose with a suitable strainer, all with standard couplings. If desired, 250 feet of two inch fire hose may be substituted.

Numerous features of novelty are involved in the production of the present pumper, and the outstanding novelty is the coordination of a num ber of features to make a practical device able to meet the demands of a wide field.

From my study of the prior art both in this country and in Europe, I believe it is broadly new to provide in a mobile pumper a compact, selfpriming centrifugal pump of the type herein disclosed and having suflicient capacity and delivery pressure to serve as a fire pump and at the awn-032 operating condition, and which pis-capable of being --:transported and put v: intogzoperationrexpedi- I 'tiously :by one man. I I

, 'The pumperhereinz=disclosedas :the preferred formiof-my invention provides therefore the fol- 'lowingsmainfeatures ofnovelty:

. x 1. The unit-has lowmenough weight and low' -frame and extend over the :top :Of :the -w e s' 4-4. The main frame c mrrises a generall rectangular m in porti n hav n l ngirtud nal sills 6-6 along. the ,outer sides 'these sills being-.ex.-

tended forwardly and cnnvergin-gcto form a relatively narrow frame ,orftongue 1 which-atits from; end, is provided with .a universal jointor enough centenofi-gravity:to beiable toytravel ,vi-rtually gas a =partpof axpassengerrautomobile.

2; Theunit' is constructed sotthat hauling or roughhandling will not! incapacitate it or inter- ;fere :with the. adequategperformance..of'..any ,of its -intended functions. I

' '3. 'I'he unit'provides .a compact but convenient assembly of all the necessary equipment for throwing water upon the fire so'that nothing will be10st0r forgotten,

4:1 The unit embodies 'a pump which is of the simplest possible type with nothing that can be injured or interfered withi by the. conditions unrder which it must work; v

5. The unit comprises a centrifugal self-priming pump preferably of the hydraulic balanced typegemp'loying a .charge-ofzpriming liquid and "hav-ingwmeans for associating the necessary charge of primingv liquid with theipump so that 'the pump may promptly be'put into operation. to evacuate its suction pipe when the'need arises. 6. The unit has. sufficient 'power and capacity tobe effective for fires in such buildings aswould 'befound in farms summer resorts, farm homes and small communities.

. The unit is capable-of being transportedand operated'byone man. 1 e v I Now in -order to acquaint 'thoseiskilled inthe art with the manner of constructing and operating my invention Ishall describe, in connection withethe ac'companying drawings, a specific em bodiment-of the same. In the-drawings: Figure I is a perspective. view from the left and front-side-of the unit of a mobile fire pumpe'r embodying my invention;

-Figure "2 is a perspective viewtakenfrom :the

rightrear of the-unit; I 1

Figure 3 is. a longitudinal vertical. section through the unit; l Figure 4' is a fragmentary vertical sectional view: through the packing gland of .the unit;

. [Figure 5 is a fragmentary vertical section through the -throating, ofthe pump taken on the line 5-5 of Figure 6;

' Figureao' is a section taken on the curved line -5;6 ofFigure'S; Ffigure '7 is a fragmentary development of the main throat opening shown: in Figure .5; and

'modified'form of throat opening. i 1 -The unit herein shown comprises a main'chase -sis-frame I supported on semi-elliptical vehicle springs 2-;2, these in turn being supported-upon *dles forming theyg'ends of the axle 3. r :Suit'able ifen'ders or mudguards i' are connected to the the ground and hold the frame I insubstantially level position.- The length of the frame is such, both jOl'WaTd and rearwardly of the axle, that pair of supplemental longitudinal bars or sills 2-5' 25 carry a cross bar 26 whichsupports-the rear end of the pump 24, a suitableipador foot 21 under. the trap 28 of the pump 24 beingpro- .1 to the automobile.

swiveled connection 8 the rear-end of Which-is connected to the tongue and the front. part of which is connectedto the universal bumper hitch or clamp 9 which is arranged to be attached .to any standard or usual automobile bumpfirgbar and securelyv fastened thereto. The specific form ofxbumper bar clam-p may obviousl h e-varied. If, desired, safety chains may connect-the bumper bar clamp; to the tongue 'ltosupplement, the universal coupling 8. r A cross barhandle-lll at the front of the tongue -provide's"means;for manually, moving the unit *asmay be necessary toraise or lower the tongue l for connectionwof the bumper bar clamp ".9 A leg [2, with a suitable foot 13 extends. through a bracket at the front of. the tongue land a clamp is provided "for holding the leg inany adjusted position. (In like manner, an adjustable :leglli withits foot]? is disposed in a bracket yl8 connected to the transverse frame; member I5 at the-rear. of the unit. Thislegis likewise adjustable and retractible. When the unit is preparedto travel the legs [2 and I6 are raised to their uppermost is-to be. set into position to operat to pump liquidrthe legs I2 and t6 are lowered to engage the'unit cannot tip up or downto an undesired angle,;since that would make it difficult for the operator to restore it tothe level con-dition.

The two longitudinal sills .5- B are connected together by the transverse frame'member {that the front end or tongue portion and by thetrans- I verse frame member l5 at the rear end, and ad the front end ofthe engine 22.= The crossbar l9a provides asupport for the rear ,end.of the engine 122 and the front of the pump 2.4 A

vided to support the rear end thereof. Supplemental sills 25-25 serve in conjunction with'the main longitudinal sills 6-45 to support the ho se "Figui'e 8-is'aview-similar to Figure 7 of a wells 3ll-30 which are arranged on oppositesides provided with a filler cap 34. Th exhaustfrom [the manifold is led up through the hood 3i to a mullier at the top of the engine unit. A car buretor 36, provided with a drain and connected between the fuel tank and the intake manifold f of the engine supplies theengine with fuel.

Arsuitable crank 31 is carried with the En -inc and asta tinsa ontrol-is con enientl pla ed: near In the upper .part of the hood 3| there is housed a fuel tank th handle as indicated at 38. The engine is provided with a speed governor and the adjustment for the control of the speed governor is pro vided with an external operating knob 39, Whereby the speed of the engine may be regulated. For

example, during the warming up period the speed may be relatively low and, upon bringing the pump up to pressure, the speed may be increased to approximately 3000 R. P. M.

The engine has its own internal oiling system, as provided through a sump 40 in the crank case. The rear end of the crank case and frame, of the engine is extended inthe form of a bell housing to contain the flywheel and providing a suitable bolting flange for receiving the front end of the open circular bracket 43, the rear end of which is bolted to a boss t4 on the main frame of the pump 24. The main frame 45 of the pump contains the impeller chamber in which is disposed the impeller 45, this impeller being mounted upon the impeller shaft 41. The impeller shaft 41 at its rear end has a disc 48 welded thereto and the disc, in turn, is bolted to the flywheel 49 of the engine 22, so that the impeller shaft 41 forms, in fact, a rigid extension of the crank shaft to the engine. The pump body 45 is provided at its upper end with a neck 50 which terminates in a bolting flange 52 to which is bolted the corresponding flange 53 of the separator 54. The main pump body 45 provides a concentric type of casing for the open impeller 46 and it provides, in the neck portion 50, the main discharge passageway 55 and an auxiliary or priming passageway 56. The impeller 46 sweeps the concentric casing with not substantially more than mechanical clearance of about air" on the side, and a tip clearance of approximately s" in the particular embodiment here shown, although this may vary for different sizes of pumps. The main and auxiliary passageways 55 and 56 in the neck 50 have corresponding mating passageways (not hown) in the lower part of the separator 54. The pump is of the type disclosed in my prior Patent 1,578,236 and its detailed structure and mode of operation are fully disclosed in my copending application, Serial No. 289,757, filed August 12, 1939, now matured into Patent 2,291,- 478 of July 23, 1942, to which reference is hereby made.

The separator 54 comprises a hollow body in which the mixture of air and water discharged from the impeller to the main throat and passageway 55 during priming, carries air out of the pump casing and evacuates the suction line during priming. This separator 54 has a central top opening by way of the elbow fitting 58 and vent pipe 59 which is left open at all times, this vent pipe leading down to a point below the adjacent operating parts and permitting the evacuation of air during priming when the discharge of the separator 54 is closed. The pipe being open also permits the discharge of water when the separator 54 is; under water pressure, but the tube is so small and the flow constriction so great that the escape of water here is negligible. A flexible tube 60 is connected to the inside of the separator and leads to a pressure gauge 62, which is mounted on the back side of the separator 54, as will be apparent from Figure 2. The separator 54 has an outlet boss 63 in which there is threaded a fitting 65 having two branches 6555 each provided with a shut-off cock 6666 and each branch having a threaded outlet covered by a cap which is internally threaded to fit the threads of the outlets, the threads of the outlets bein standard fire hose coupling threads adapted to receive the female coupling 6'l6l of the lengths of hose 68BB carried in the hose wells 3030. The threaded caps 69 are tethered by means of short lengths of chain 10 to the corresponding branch outlet 65, so that the same may not become lost.

The primary purpose of the pressure gauge is to show when the pump has filled itself with liquid by emptying the air from the suction pipe and is ready for discharging water. The secondary purpose is to indicate whether the pump is giving the desired pressure upon the hose and nozzles when the pump is employed in actually throwing water upon the fire. During the time that the pump is evacuating the suction pipe, that is, while it is pumping air, the pressure in the separator does not rise substantially above atmosphere because of the open air vent. As soon, however, as the air has been evacuated from the suction pipe, and the pump filled with liquid, the valves 66 being at this time closed the outflow of liquid from the separator through the air vent is so greatly restricted as to be negligible, and consequently, the pressure in the separator rises sharply at the moment that the pump has attained itsprime. This is a very useful indication. 4

The hose wells each contain four rolls of 1 standard fire hose, each roll containing 50 feet, and the rolls being held in place by partitions between adjacent rolls, these partitions being parallel sheet metal partitions. The rolls are further held in place by flexible straps or bands 12 fastened at each side to the sides of the cylindrical or drum-shaped hose wells and buckled together to hold the rolls of hose definitely in shape.

The body 45 of the pump in which the impeller chamber is disposed has a cylindical recess upon the back side of which is formed the boss 44 heretofore mentioned and also a boss 12 which is bored out to provide space for the fibrous packing 13, which is held in place by a follower 74 which has an intermediate lubrication connection by way of the tube 15 and grease cup 76. The rear of the follower 14 is counterbored to provide space for the supplementary packing 11, and the grease from the grease cup 16 is introduced into an annular chamber between the two packings l3 and ll to lubricate the main packing. An auxiliary spring pressed follower l8 engages the auxiliary packing 11 which seals 01f the lubricant chamber. This auxiliary follower !8, which is free to move along the length of the shaft 47, is pressed against the auxiliary packing 71 by means of the coil spring 19, which is under compression. The opposite end of the spring presses against a flange in a threaded sleeve 82, which sleeve is threaded into a central hub 83 formed in the cylindrical mounting bracket 43. The sleeve 82 has at its front end a head which is provided with capstan openings 84 into which a pin may be inserted to turn the sleeve 82 upon the threads in the hub 83, to thereby ad- Vance it towards the follower 74 or to retract it.

The operation of this sealing device is believed to be apparent from the above. The threaded sleeve 82 which contains the compression spring 19 provides a spring abutment for the spring 19 whereby the spring ma force the auxiliary follower 18 against the auxiliary or sealing packing 11 in the main gland follower 14 and-this gland follower 14, in turn, is

pressed against the main packing 13 on the pump 2-,-se'r,o32.-

videcl with drains 93* and-94,- respectively, for

shaft; 4,1?tct seaEita against. passage. of fluid along thashaft.

vided'to prevent it, thepressure of the'water inside the pump might blow thelpacking- 'I3cand the follower T4'out of the recess in the" hub 12 and thereby unseal the pump. Obviously, it would not do to put sohigh aspring .pressure on the follower as to overcome this pressure, for then if the pump were operating on 'a suction the spring pressure would be'excessive, the shaft would heat and score, and the pump might be damaged. The sleeve 82 and its auxiliary spring pressed packing gland follower serves-to meet this troublesome problem, in that the spring 19 is put-under a definite predetermined stress, that is, itis prestressed by a definite amount, and the sleeve: 82 islong enough to' reach the" 'main' gland follower M andtheteby limit furthe'r stressing of. the spring 19 but toapplyza direct pressure to the said follower I4 by'enga'ging'the same endwise. Nowit can-be seen that by the *engagement between the head ofthe'sleeve-8 2 and the follower 14; internal pressure on the pump cannot blow thepacking I3 out because the gland follower 14 is rigidly supported by thesleeve82. As soon as internal pressure is relievei then "the spring" 19 again resumes control of thepressure which is not resilientand'will not follow up'except as it is advanced" on the threads. As the packin 1wears, the spring follower '18 will automatically take up thewear and willp'ush] the main "gland follower 14 awa-y fr'om thehead of the sleeve 82,

drainirigthapump, particularly for coldweather;

Theinlet trap- 28 has an inlet connection 95 in-towhich isthreaded anipple 96 hearin at its outer end. a standard suction hose fitting 9'! provided with threads ,adaptingthexsame for oooperation with the internally threaded cap 98 which normally closes the 'inlet connection, or for connection with the femalehose eoupling 99 of the suction hose I00, or, alternatively, with the female connection 99-of the suction hose lengthlB-Z. =The-hose1lengths I00 and H12, respectively, are preferably 12 ft. standard 3" fire enginesuction hose, the lower length I02 bearing at its outer end a suction,

strainer I 03 provided witha large number ofslots, in: accordance; with known j practice in the art. Theremote end of suction hose length I00 is provided with a male threaded coupling 14 so that the two lengths H10 and |02-may be connected in series-to the intake of the pumps The, nipple $26 isnotessential, but preferably it is, of a length which'will-carry the threaded male fitting out to a point beyond the adjacent hose wells 30-30-so that a suitable spanner wrenchwhich is employed for couplinggfire hose maybe applied and used without'interference: from the hose wells. The

intake connection95 lies well above the frame I whereit is readily accesible at all ti es.

The two lengths of hose I00 and I02 are'bent into U-shape and the'bottom of the 'U-is placed in front of the radiator 32 of the engine, this being desirable, first of all, to protect the radiator from material thrown up from the road in course of the run, and also tending to insure that-the hose will not be shaken off in the event" that the flexible straps which hold the hose'in place should become loosened. The sides of the-1U shaped lengths of hose preferably rest uponjhose boxes I05-|05 which are disposed 1ongitudinally of the side framesills 6'-B and which are adapted each-to contain'alength of ft. 1 /2" hose. Ob-

; vi'ously, instead of carrying 500' feet of I /Z' hose',

and this gap may be taken up from time totime,

but if the pump is put-underpressure at such time asa gap existsbetweefi the follower and. the

head ofthe sleeve 82, no greater injury is done than toshiftthe-follower!!! back against the abutment of the sleeve 82"." This arrangement of positive 'abutment'and spring follower is highly advantageous for this service or, in fact, for any desiredservice where the pump may befsubjected to internal pressures'of greater'or less value than atmospherei I The cylindrical recess in which the impeuer'as ,is disposed is closed on'the rearside by an inlet and sidef'plate- 84having a tubular neck 85'definber 8 4 'ha s a flange 86 which is engaged by' the annular flange 'B'lfof the inlet trap 28; the fiange of the' inlet tra'p2fi and the margin of the main pum'pqbo'dy 45" being held 'togetherby suitable bolts, such as 8'8 as shown in Figure 4. Thefinlet trapds provided with a cap or cover89; at its upper end, this closure 89 closing a cleanout opening andbeing held normally in place by a-C-clam'p 90' "and; a clamping screw' 9 I. v A basket-shaped inlet" screen '92 is disposed in the trap directly below the cleanout opening'f and is intended; to strain out such "solids as would tend to interfere withftheioperation of the pump itselfi This strainer is'desirable-particularly since the suction of the pump maybe disposedin' any casual wateri 4 Thef'inlet trap2'8 and the pump body are-pro a shorter length of a larger diameter hose,--suci1, for'example; as 250 feet of 2" hose, may besubstituted. k 1

The specific arrangement of the partitionsin thewells- 30-30' andthe size of these wells may be varied, within suitable limits. Flexible straps attached tojthe frame'are buckled over the boxes I05 and the adjacent lengths of hose, -as'=indi'- calted at I06 in'Figuresl and 2, and the'front part of the'suction hose may be carried in forkshaped brackets mounted on the frame I, suitable flexible straps "such a I U'Igoing over the hose 7 to hold the same in position. The hose wells 3!! are located aft of the axle 3 and the hose sup- .ing: the inlet passageway'from'the inside of'the trap 28. The outer margin of the side plate meme ported in these wells therefore tends to make the unit unbalanced. However, the suction hose, which'is quiteheavy, extends around andcompletely in front of the engine 3!, as will be seen in Figure- 1, and tends to counterbalance the hose in the wells in the rear. Thus with the engine pump unit substantially balanced over the axle, and the hose likewise substantially balanced fore and aft overthe axle, the unit is, whether in use or in transport, substantially in balance over the axle, and therefore at all times relatively stable The pump, as above mentioned, is fully disclosed in my oopending-application, Serial No. 289,757, and it comprises'a compact, highly efficient self-priming centrifugalpump capable of delivering 150 gallons per minute at lbs. per square inch at the delivery end ofthe hose, with the'engine-cperating at 2850 R. In the" lengths of specific pump illustrated the impeller diameter is 9%" in diameter by A in width; the pump primes very rapidly, and will draw a dry vacuum of 28 inches of mercury at an elevation of 746 feet above sea levele. The port arrangement and throating is shown in Figures 5 to 8, inclusive. The throat III) of the main passageway 55, in shape is preferably that shown in Figure 7, and while it has rounded edges and rounded corners it is of the general shape of an elongated opening, the width being not substantially greater, but preferably less than the width of the channel H2 in which the impeller 46 operates. In the preferred form of throat opening as shown in Figure 7 the most constricted part of the opening between the pumping channel and the separator is at the port, that is, next to the channel, and the passageway 55 has a gradually expanding cross section into the separator. In the preferred form of throat opening shown in Figure '7 the advance end is slighly wider than the trailing end. The advance end H3 is of approximately the same width as the channel I I2, whereas the trailing end is substantially narrower.

A port opening of the form shown in Figure 8 has shown excellent results but not quite as good as theform shown in Figure '7. The slot opening H0 shown in Figure 8 has a slightly constricted advance portion I I3, and from there on to the rear portion H4 the port opening is of substantially uniform width less than the width of the channel H2. I

As explained in my said copending application, reducing the width of the port opening to less than that of the active or effective width of the impeller, reduces the eddy currentlosses in the throat, allows development of a higher pressure, and markedly increases the efficiency of the pump.

It appears that the outermost high energy content layer of water is distributed along the length of the port opening instead of being all discharged at the initial part of the port opening. The pump therefore holds its pressure over a wider range of deliveries and permits the use of a smaller pump and engine in the unit, which is of a very great advantage in this particular service.

The operation of self-priming centrifugal pumps of this type is known. Suflice it to say that the pump is provided with a suitable priming charge which is trapped in the intake trap and in the impeller chamber. Upon startingof the engine, assuming that the suction hose is connected and the end thereof sealed with water to be pumped, the initial operation is to drive water into the separator 54, whereupon a part of the same returns by gravity through the passageway 56 and to the throat H5. The throat I I5 is preferably of the same contour as the throat H0 or III), inasmuch as it serves, during liquid pumping, as a discharge throat. During priming, however, the return of liquid at the throat H5 results in the impeller forming a mixture within the pumping chamber and channel and dischargthrough the throats H0 and H5 into the separator 54 and from thence on out to the nozzle and is there discharged. As the pump develops suction, the return of liquid to the return passageways 56 tends to increase in rate of flow due to the difference in pressure. The discharge of mixture through the throat I I0 proceeds at a higher rate unless the excess of return liquid is such as to flow past the throat Hi] and automatically cut off or reduce the return flow at the throat 55. This is known operation of pumps of this type.

The operation of the device as a whole is as follows: The unit, as shown in Figures 1 and 2, normally stands with liquid charged into the pump to a suitable level, which normally is not any higher than the intake connection 9'5. In other words, the pump contains its own charge of priming liquid prior to going into service. The closure caps 98 of the intake and 65, of the discharge connections are normally in place, completely sealing off the inlet and dis-charge passageways of the pump so as to retain the liquid therein while the pump is standing idle and during transportation to the place of use.

If the unit is to be stored in a cold building during severe winter weather, the charge of liquid is preferably drained off through thepetcocks 93 and 94, these petcocks thereafter being closed. and a charge of water containing anti-freeze ingredient is providedin a can or .container which preferably is strapped in place on the frame under the intake connection 96 in such position that it cannot be dislodged during a run of the pumper. When such a can of lowfreezing temperature liquid is employed for the priming charge the front end of the pumper maybe lowered to the ground,-tipping up the intake connection, the sealing cap 98 is removed, and the liquid is poured from the container into the pump. Obviously, alternatively, the non-freezing liquid may be poured into the pump at any time before the run is made and retained in the pump without danger of freezing. When it is desired to convey the pumper to the place of use, an automobile may be backed up to the front end of the pumper. The operator then raises the rear leg I5 and looks it in raised position. The pumper is slightly overbalanced in a forward direction so that it will not tip up backwardly when the foot I6 is raised. The suction and discharge hose do not substantially unbalance the pumper fore and aft of the axle when the same are in place. By means of the handlebar ID the front end of the frame may be raised to dispose the bumper clamp 9 over the bumper of the automobile. The clamp is then made fast, and the leg I2 is raised and locked in raised position. The unit is then ready to proceed. This may be accomplished by one man.

Obviously, if desired, the engine may be started at this time in order to warm up the engine during the run to the fire. Starting the engine prior to its arrival at the place of use is not essential. The automobile drawing the pumper may proceed at any convenient road speed, as the pumper will travel with the hauling car over substantially any road that the hauling car can travel and at almost any speed that the hauling car can attain. The .driver may proceed without any attention to the unit. Upon arrival at the place of intended use, the pumper is hauled by the automobile to a point as near to the source of Water as is feasible. The clamp 9 is unhooked and the pumper is pushed by hand to the desired place or location of use, whereupon the legs I2 erably employed for that purpose.

, I assume and" ltare'drc ped and l'ock'edintoplace'. i This" above described, andoperation ofthe engine will not-throw the same out the dischargebe'cause' the valvesfifi are closed and the closur caps'liS are in place. It is important tokeep the shutoif valves 66 closed when the engine is started up because the: engine'unde'r"governor control starts'with' wide open throttle and'jump's up togovernorspe'ed. This high acceleration up tothe speed at which the engine governor is set, even if s'et'at relativelylow'speed, tends to throw some of'the priming water out of the discharge. The

loss" o-f'priming water is undesirable as it tends to reduce or destroy the priming ability of the pump. The suction hose lengths I and I02 areth'en' coupled to the intake connection 91, the cap 98 being removed, the hose couplings are drawn up tight, since air admitted to the sue.- tion is undesirable, a spanner wrench being pref- The spanner wrench may be carried in the tool box H6 (see Figure l), a suitable box of this character being disposed on each side of the frame for carrying tools, fire nozzles and, if desired, a starting, battery for the engine. As soon as the suction hose is connected and the strainer I03 covered with water to be pumped, the engine may be speeded up to prime the pump. This allows the pump the discharge hose is being coupled. The air which is withdrawn from the suction hose and driven over into the separator is expelled through the vent pipe 59, the valve 66, preferably still to prime the pump the discharge hose may be connected to each of the branches, the sealing caps 69 being removed. Even if the pump has developed pressure, nodischarge of water interferes with the coupling up of the discharge hose, because the delivery is closed off by the valve Such closing oiT of the delivery of a centrifugal pump operating under pressure does it no harm, since the impeller merely slips in the impeller casing. As soon as the discharge hoses are connected and the nozzles fastened in place, the operator can see by the pressure gauge 62 whetherhe has delivery pressure and if the prime has been completed and pressure devel-' oped. He thereupon opens the corresponding Now? it} will be" observed that the maximum personnel-required tohitchup, transport to the .to effect its prime and develop pressure while being closed. While the engine isthus running place' o'f use, couple 'up the hose, open the valve, andthro'wwaterupon the fir'e, is one man. In brief, one man can perform in sequence all the required operations'totransport the pumper to the-fire, put the pumpe'r' into operation, and tnrowwater on thefire to put it out.

A feature of prime importance is the inherent se'lf p'rirning ability or the pump. When the suction hose is coupled up, and the strainer end droppedinto" the water, the pump will automatically' pick up its prime without any attention from the operator." Also, if the suction strainer should become uncovered; or the pump should draw in'air, the pump will not become air bound, but will; as soon as water is again available, pick up its'prime'and proceed to discharge the same.

The feature of insuring that a charge of primingliquid'will be retained in or with the pumper, sothat When'it arrives at the place of use it will be immediately available, is important, since quite. frequently: it is highly'inconvenient to secure any liquid to form the priming" charge when the pumper is to be used. When it is desired to carry the priming charge in a separate containerthis container, with antifreeze liquid or any other type of liquid suitable for the conditions therein, is secured upon the frame of the pumper preferably being strapped or clamped in place under the intake nipple 96 and resting on sills 2525. A cradle for this container may be provided if desired. Thus the charge of priming liquid is definitely associated and carried with the It is to be observed that there are no loose parts except as they are disposed in fixed relation to the unit. The device is complete and operative, even to the firemans axe H1, which is fastened to the frame.

The pump automatically supplies itself with liquid from the source by virtue of the priming charge, but even if the priming charge were not supplied or inadvertently lost the pump might 'yet be primed by applying suction to the vent Such contingency is not likely to arise.

shut-off valves 6666, and thereupon the pumper throws water upon the fire. The governor adjustment-39 may be regulated during these operations to give the desired speed of theengine' and delivery pressure of the pump.

To take the unit out of service the suction and delivery hoses are disconnected and replaced, the sealing caps are again applied, the hoses strapped down, the unit is connected to the bumper of the automobile by means of the clamp 9, the. legs l2 and I6 are raised and locked in raised position, the engine. being stopped in the meanwhile, and the pumper may then be run back to its shed. As soon as it is returned to the shed the pumper should be drained and cleaned out, and either provided with a fresh charge of priming liquid inside of it, or in the associated container suitably strapped into place, so as to travel with the pumper.

The self-priming pump is highly advantageous in. picking up its own prime rapidly and efliciently, being able to handle dirty water, water with entrained solids, and to provide a satisfactory delivery at, a satisfactory pressure and at high efficiency in a small, compact unit. It is also very valuable in being able to take any casual air or gas and quickly evacuate the same without being put out of operation. The priming structure does not interfere with the capacity nor limit the pumping ability of the pump. nor reduce its efiiciency.

When the pumper is to be constructed to deliver pressures substantially higher than that is hereby made for a detail disclosure.

The reason for going to a plurality of stages resides in this, that the center of gravity of the pumper as a whole must be kept low so that it can travel with the hauling automobile without danger of overturning. Increases of diameter of the pump casing 45 tends to increase the Weight and height of the center of gravity. While I may keep this down by making the pump casing and separator of aluminum, it tends to require raising of the crank shaft of the engine and raising its center of gravity which is undesirable. The preferred arrangement and the one Which I have in the present unit been able to attain is to keep the center of gravity so low that the pumper can travel with the automobile Wherever the automobile can go, and at substantially any speed the automobile can draw it.

By my invention there is provided a complete self-contained unit, large enough to be effective, i. e., capable of developing high enough pressure and throwing sufficient Water to make an effective fire fighter, and at the same time, capable of use by limited personnel, if necessary, by one man.

Obviously, I do not intend to be limited to the precise details shown and described, as the' preferred embodiment is but an exemplification of my invention.

I claim:

A self-priming centrifugal fire pump suitable for use in a mobile fire pumper comprising an impeller casing having intake and discharge passageways, an intake trap connected to the-intake passageway of the casing, a separator connected to the discharge passageway of the casing, said trap having a horizontally extending suction connection provided with a quick detachable suction hose coupling, means for shutting off the suction connection to prevent loss of contained priming liquid during transport of the pump, the separator having a horizontally disposed discharge connection provided with a quick detachable discharge hose coupling, a shutoff valve between the separator and the coupling, and a restricted air vent connectedto the top of the separator for permitting the discharge of air from the separator While the pump is priming and the valve is closed.

HARRY E. LA BOUR. 

